Research Papers: Gas Turbines: Structures and Dynamics

Rotor Model Updating and Validation for an Active Magnetic Bearing Based High-Speed Machining Spindle

[+] Author and Article Information
Jerzy T. Sawicki

Fellow ASME

Alexander H. Pesch

Center for Rotating Machinery Dynamics and Control (RoMaDyC),
Cleveland State University,
Cleveland, OH 44115-2214

Contributed by International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received June 21, 2012; final manuscript received June 30, 2012; published online October 25, 2012. Editor: Dilip R. Ballal.

J. Eng. Gas Turbines Power 134(12), 122509 (Oct 25, 2012) (6 pages) doi:10.1115/1.4007337 History: Received June 21, 2012; Revised June 30, 2012

This paper presents an experimentally driven model updating approach to address the dynamic inaccuracy of the nominal finite element (FE) rotor model of a machining spindle supported on active magnetic bearings. Modeling error is minimized through the application of a numerical optimization algorithm to adjust appropriately selected FE model parameters. Minimizing the error of both resonance and antiresonance frequencies simultaneously accounts for rotor natural frequencies as well as for their mode shapes. Antiresonance frequencies, which are shown to heavily influence the model’s dynamic properties, are commonly disregarded in structural modeling. Evaluation of the updated rotor model is performed through comparison of transfer functions measured at the cutting tool plane, which are independent of the experimental transfer function data used in model updating procedures. Final model validation is carried out with successful implementation of robust controller, which substantiates the effectiveness of the model updating methodology for model correction.

Copyright © 2012 by ASME
Your Session has timed out. Please sign back in to continue.


KoelschJ. R., 2001, “High Speed Machining; A Strategic Weapon,” Machine Shop Guide, Smith Publishing Inc., Garden City, NY.
BadrawyS., 2001, “Cutting Dynamics of High Speed Machining,” Wolf Trecks, 8(1), pp. 24–26.
Chen, M., and KnospeC. R., 2007, “Control Approaches to the Suppression of Machining Chatter Using Active Magnetic Bearings,” IEEE T. Contr. Sys. T., 15(2), pp. 220–232. [CrossRef]
Schweitzer, G., and MaslenE. H., 2009, Magnetic Bearings: Theory, Design, and Application to Rotating Machinery, Springer-Verlag, Berlin/Heidelberg.
Friswell, M., and MottersheadJ. E., 1995, Finite Element Model Updating in Structural Dynamics, Kluwer Academic Publishers, Dordrecht, The Netherlands.
Xiong, Y., Chen, W., TsuiK.-L., and ApleyD. W., 2008, “A Better Understanding of Model Updating Strategies in Validating Engineering Models,” 49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Schaumburg, IL, April 7–10, Paper No. AIAA 2008–2155.
WroblewskiA. C., 2011, “Model Identification, Updating and Validation of an Active Magnetic Bearing High-Speed Machining Spindle for Precision Machining Operation,” Doctoral dissertation, Cleveland State University, Department of Mechanical Engineering, Cleveland, OH.
Sawicki, J. T., and MaslenE. H., 2008, “Accurate Identification of Plant Model for Robust Control of an AMB Machine Tool Spindle,” Ninth International Conference on Motion and Vibration Control (MOVIC 2008), Munich, Germany, September 15–18.
Sawicki, J. T., and MaslenE. H., 2007, “Rotordynamic Response and Identification of AMB Machining Spindle,” ASME Turbo Expo Conference, Montreal, Canada, May 14–17, ASME Paper No. GT2007-28018. [CrossRef]
Sawicki, J.T., and Maslen, E.H., Bischof, K.R., 2007, “Modeling and Performance Evaluation of Machining Spindle With Active Magnetic Bearings,” J. Mech. Sci. Tech., 21(6), pp. 847–850. [CrossRef]
MarwalaT., 2010, Finite Element Model Updating Using Computational Intelligence Techniques: Applications to Structural Dynamics, Springer-Verlag, London.
EwinsD. J., 2001, Modal Testing: Theory, Practice and Application, Research Studies Press Ltd., Hertfordshire, England.
WuY.-X., 1999, “Sensitivity-Based Finite Element Model Updating Methods With Application to Electronic Equipments,” Ph.D. thesis, Polytechnique de Mons, Mons, Belgium.
YangW. Y., CaoW., ChungT.-S., and MorrisJ., 2005, Applied Numerical Methods Using MATLAB, John Wiley & Sons, Inc., Hoboken, NJ.
Nelder, J. A., and MeadR., 1965, “A Simplex Method for Function Minimization,” Comput. J., 7(4), pp. 308–313. [CrossRef]
Sawicki, J. T., and MaslenE. H., 2008, “Toward Automated AMB Controller Tuning: Progress in Identification and Synthesis,” 11th International Symposium on Magnetic Bearings (ISMB-11), Nara, Japan, August 26–29.


Grahic Jump Location
Fig. 1

Top: spindle cross section. Note that the drawing does not include the tool holder. Bottom: spindle photo.

Grahic Jump Location
Fig. 2

The FE rotor model with subregions designating the structurally uncertain elements

Grahic Jump Location
Fig. 3

The open-loop model (solid lines)

Grahic Jump Location
Fig. 4

Transfer functions from the front (top) and rear (bottom) AMBs illustrating the nominal model and experimental data

Grahic Jump Location
Fig. 5

Transfer functions from the front (top) and rear (bottom) AMBs illustrating the updated model and experimental data

Grahic Jump Location
Fig. 6

Mode shapes of the first two bending modes illustrating the updated model and the experimental data

Grahic Jump Location
Fig. 7

Transfer functions from the front (top) and rear (bottom) AMBs illustrating the updated model (excluding antiresonances) and experimental data

Grahic Jump Location
Fig. 8

Mode shapes of the first two bending modes for the updated model (excluding antiresonances) and the experimental data

Grahic Jump Location
Fig. 9

Experimental and simulated stiffness of the spindle at the tool plane for the μ-controller and the PID controller




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In